Reading the forums in the last week, I came to the conclusion that it won't be possible to please everyone with one single game. But maybe this is not necessary. Why not publish 5th edition as three separate, complete and self-contained games? D&D Core, D&D Legends, and D&D Tactics.
Each is targeted at a different audience, but all games are compatible enough that you could "guest star" with a PC from one game in another, or completely convert him if you switch groups.
If each of these is modular, groups can mix and match the elements. You could play a rules-light game as per D&D Core, but add some tactical battle rules like opportunity attacks from D&D Tactics, and character backgrounds from D&D Legends.
This also makes it easy to describe your campaign to others, compared to a game where there is one core and unsorted options.
D&D Core
Target:
* New players who don't want to be overwhelmed by rules
* Players who like OD&D, or retro-clones
* Players who like rules-light games
* Players who like classic dungeon crawls
* Convention games
* Players who like it straightforward, but hardcore
This represents the "core" of D&D, and the game the other two are based on. In the PHB, it contains Fighter, Rogue, Wizard, and Cleric, Human, Elf, Dwarf and Halfling. The rules are simple and straightforward, and can be explained in less than an hour. There are some modernizations, such as 3E-style ability score modifiers and ascending AC, and a very basic skill system, but the essence and the playstyle are very much like the Red Box.
There are Core-only splatbooks, but these don't add to the rules framework, but rather contain equally rules-light player options, such as additional races, classes and spells.
Since this game targets newcomers, it will come with plenty of player and DM advice. It also includes some optional rules that lead to either D&D Legends or D&D Tactics, to give groups a preview who wish to move towards a more complex rules system and help them find the playstyle that fits them best.
Optional rule: Tournament Mode. This is where the gloves come off, old school. Includes a standard module for competitive play, with detailed point scoring depending on how well the group did.
Note: Easy introduction for newcomers and compatibility to the other games is more important than faithful replication of old editions. This game should not adopt retro rules like level caps for non-humans for retro sake.
D&D Legends
Target:
* Players who like AD&D
* Players who liked 3rd edition, but never bothered with miniatures
* Players who like storytelling-focused systems like 7th Sea
* Players who write long backstories for their characters
* Players who read fantasy novels
* Players who have played a child of one of their PCs
Based on Core D&D, but enriched with elements that support storytelling, intrigue, and in-character play. Rules expansions concentrate on character backgrounds, perks & flaws, NPC relations, reputation, social status, and similar story-driven and story-driving rules.
Combat rules are focused on narrative. Players are expected to describe their actions, and the DM interprets it with a flexible framework. No miniatures or battlemat. Action points allow players to take control of the narrative.
Big focus on social interaction, and social conflict rules.
Optional rules for spontaneous magic (making up spells and effects on the fly).
Includes background material on organizations, and how players can act within these.
Optional rules for joint DMing.
D&D Tactics
Target:
* Players who like 3rd edition, but thought the Fighter needed fixing
* Players who like 4th edition, and especially the Warlord
* Players who like Final Fantasy Tactics and Risk
Based on Core D&D, expanded by no-holds-barred miniature skirmish battle rules. Attacks of opportunity, tactical movement, interrupt powers... Each class has a clear combat role attached, and is tightly balanced to other classes. There is a big focus on making each class interesting and useful. Action points do cool stuff.
Includes skill challenge rules to deal with non-combat situations.
Rules expansions include mass combat, naval warfare and siege rules. Rules for strongholds and followers.
This book has very little "fluff", and focuses on "crunch".
"Super-D&D"
Use both D&D Legends and Tactics at the same time, with all options enabled (Core is included in both anyway).
Combats will be run from Tactics, while the storytelling will be taken from Legends. This works because each book expands a different element of the game, and they are based on the same Core rules.
This will work best with groups that either like both aspects of the game, or with large groups where players have different interests, but the DM leaves them space to focus on their interests.
The books need a chapter with guidance on how to combine both directions.
